1. Field of the Invention
The present invention relates to a tape carrier package, and more particularly to a foldable tape carrier package which electrically connects an LCD panel with an LCD driver printed circuit board. Further, the invention relates to an LCD module to which the tape carrier package is applied.
2. Description of the Related Art
In thin film transistor liquid crystal display (TFT-LCD), gate driver printed circuit board (PCB) that drives gate lines and source driver PCB that drives source lines are respectively disposed apart by a selected distance from long and short edges of LCD panel.
Tape carrier packages (hereinafter referred to as xe2x80x9cTCPxe2x80x9d) are used for electrically gate and source driver PCBs with LCD panel apart from the PCBs.
TCP is a kind of packages wherein input and output lines, that is, leads are printed on a flexible insulating base film and a chip that is connected with the leads is mounted on the base film. The leads are covered with a resist film except for a selected portion from the both ends.
When gate and source driver PCBs that are connected with the TCP are placed on the same plane with the LCD panel in the LCD module product, the module size becomes larger unnecessarily compared with the display region of the LCD module. Accordingly, it has been provided that such the PCBs are attached to the backside of the LCD panel using the flexibility of the TCP.
Fukuta et al (U.S. Pat. No. 5,153,705, TAB PACKAGE AND A LIQUID-CRYSTAL PANEL UNIT USING THE SAME, Oct. 6, 1992) discusses a TCP in which slit is formed at a bending portion of the TCP in order to prevent leads from being broken when a large stress is concentrated on the bending portion.
As the number of leads increases due to the request of high definition in image quality and of decrease in fabrication costs, pitch between leads decreases. Decrease in pitch enhances the stress per unit area applied to the boundary between a first portion where the resist film is coated and a second portion where the resist film is not coated. As a result, in spite of the existence of the slit, a progressive crack frequently occurs at the boundary.
It is therefore an object of the present invention to provide a TCP having fine pitch leads and being endurable in the stress concentrated during the bending of the TCP.
It is another object of the present invention to an LCD to which a TCP having fine pitch leads and being endurable in the stress concentrated during the bending of the TCP is applied.
To achieve the above objects and other advantages, there is provided a tape carrier package comprising: a first flexible film made of insulator; a conductive pattern formed on the first flexible film and having a plurality of input/output leads each having an input terminal and an output terminal; a semiconductor chip having a plurality of input/output terminals electrically connected with the input/output leads of the conductive pattern; and a second film made of insulator, the second film coating the conductive input/output leads such that the input/output leads are exposed by a selected length from respective ends thereof, wherein at least one selected lead of the input/output leads disposed at at least one sided end of the tape carrier package comprises a first portion and a second portion which is wider than the first portion, the second portion extending from a first selected position of the exposed leads to a second selected position of the second film passing a boundary between the second film and the exposed leads.
According to another aspect of the present invention, there is provided a tape carrier package comprising: a first flexible film made of insulator; a conductive pattern formed on the first flexible film and having a plurality of input/output leads each having an input terminal and an output terminal; a semiconductor chip having a plurality of input/output terminals electrically connected with the input/output leads of the conductive pattern; and a second film made of insulator, the second film coating the conductive input/output leads such that the input/output leads are exposed by a selected length from respective ends thereof, wherein said output leads of the conductive pattern has at least three selected output leads disposed at at least one sided edge of the tape carrier package. Here, the selected output leads includes: (a) a first output lead including a first portion and a second portion which is wider than the first portion, the second portion extending from a first selected position of the exposed leads to a second selected position of the second film passing over a boundary between the second film and the exposed leads; and (b) a second output lead including at least two lead wires which input/output the same signal, said two lead wires combining as one body from a third selected position of the exposed leads to a fourth selected position of the second film passing over a boundary between the second film and the exposed leads, and said combining two lead wires being wider than the first portion of the first output lead.
According to yet another aspect of the present invention, the above described two TCPs are applied to LCD modules in which LCD panel and gate and source driver PCBs are electrically connected with each other.